colman



(No Model.) 2 Sheets-Sheet I. P. B. COLMAN.

ELBGTRIGALLY AGTUATED VIBRATOR.

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2 Sheets-Sheet 2.

(No Model.)

F. B. COLMAN. ELEGTRIQALLY AGTUATED VIBRATOR.

No. 367,270. Patented Ju'ly, 1887.l

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UNITED STATES PATENT OFFICE. x

FRANK B. COLMAN, OF NEW YORK, N. Y.

ELECTRICALLY-ACTUWATED VI BRATO R.

SPECIFICATION forming part of Letters Patent No. 367,270, dated AJuly 26, 1887.

(No model.)

To all whom L' may concern: y

Be it known that I, FRANK B. COLMAN, of New York city, State of New York, have invented certain new and useful Improvements in Electrically-Actuated Vibrators, of which the following is a specification. t

In some systems of telegraphy, now generally known, automatic vibrators are cmployed,and the signals are reproduced either upon a tele` phonic receiver or otherwise by throwing upon the line groupsorasuccession of vibratoryimpulses divided tocorrespond to dots and dashes of the Morse alphabet. Where lthe receiver employed is an ordinary speaking-telephone, it is desirable to employ in connection with it a transmittiiig-vibrator having a high pitch and a keen distinct sound, so that when it is thrown into and o ut'of vibration sharply-dened signals are produced in the telephonie receiver; Avibrator ofsuch a character gives better results than the ordinary tuned reeds or strings tuned to musical tones.

In the now well-known Phelps7 system of induction telegraphy, it has been proposed to employ vibrators in connection with speaking-telephone receivers for the purpose above mentioned. My improved instrument is designed more especially for use in connection with that system; but it is not confined to such a use, and may be employed wherever an electric vibrator is needed.

, vibrator, magnet, and adjusting devices, with the parts of the frame removed.

A is a bed-plate, of any suitable material, having two uprights, a a, preferably connected by a cross-piece, b. Beneath the crosspiece b a string-bar vibrator, C, is shown in suitable proximity to the poles of a magnet, M. rIhe vibrator C may be secured in place at one end by engaging alug or stud, c', upon one of the uprights ofthe cross-piece b in an aperture in the bar. The opposite end is connected with the hooked end ot' a rod, D, passing loosely through an aperture in the upright a. The outer end of therod is screw-threaded and is provided with an adjusting-nut, d, and between the hub of the adjusting-nutand the upright a is interposed a stout coiled spring, s. By screwing up the nut, therefore, an elastic strain or tension may be put upon the stringbar. It desired, the ro'd D may be clamped rigidly by a set-screw, E, working in a hub in the upright d. By this construction the stringbar may be strained to any desired tension, and the tone which it will give out when vibrating may therefore be modified as required. So far as this part of my invention is concerned it is not limited to a string-bar vibrator, but it applies to electric vibrators of different forms. For instance, if the vibrator shown Were'widened, the result would be the same,and if such a widened vibrator weresupported continuously along its ledges and held under elastic tension the resultwould be the same. This invention therefore contemplates no limit as to shape or form, but comprehends, in its broadest terms, an electric vibrator of any description which is held under an elastic or yielding tension. In this connection I am of course aware that electric vibrators of various kinds have been provided with means for straining them to produce the tone or number of vibrations desired,`and I do not claim such subject-matter.

A bridge, F, straddles the crosspiece b and carries a contact-screw, G, which passes through an aperture in the cross-piece and works in a socket in a split block, g, on the bridge F. The parts ofthe split block g may be rigidly clamped against the screw by a screw-bolt, H, working iin threaded sockets in the divided block and arranged transversely to the contact-screw Gr. This device is not new in itself and is not broadly claimed herein. It is, however, of

special advantage in the particular use to` bilityof error, because the contact is moved a distance equal to the slack in the thread of the screw when the check-nut is screwed up.

The circuit is from one binding-post, X, through the magnet M M to the contact-screw e atrevo G, vibrator, and other binding-post Y, and ried by a disk, M', screw-threaded on its outer when a circuit through the magnet M is completed by the closing of a key or any transmitting device the vibrator will be thrown into action and will automatically make and break the circuit at the contact G, as usual.

As the vibrator is liable to become heated by sparking at the contacts and also by reason of mechanical impact against the contactscrew, there is a tendency for it to elongate, thus modifying its rate of vibration and the sound emitted by it and reproduced in the telephonie receiver. To compensate for such a possibility, a series of small apertures is punched or formed in the vibrator, preferably around or near the contact thereon. These apertures serve to take up the expansion of the metal at this point and prevent any disturbance ofthe normal rate of vibration, and as the radiatingsu rfaee is increased the bar cools more rapidly.

Should any further adjustment be desired other than that afforded by the manipulation of the adjusting-nut d, it may be obtained by lengthening or shortening` the vibrator. This may be accomplished in the following manner: Alink or stirrup, I, arranged on either or both sides of the bridge F,embraces the cross piece b and the vibrator, and is provided on its upper side with a clamping-screw,which passes through the link and bears against the crosspiece b. A block of metal is loosely interposed between the vibrator and the under side of the cross-piece b, and by screwing up the bolt 'i the vibrator may be iirm'ly clamped between the block t and the bottom of the link or stirrup. As these links may be moved along the cross-piece b to any point desired, the length of the reed may in effect be changed and its tone or number of vibrations per sccond increased or diminished. As before remarked, one only Aof such adjustable clamps may be used, or two if desired, one on each side of the magnet M.

It is immaterial what means are resorted to to effect the movement of the link on the cross-piece b. The arrangement maybe such as illustrated in the drawings, in which the adjustment is effected by merely loosening the clamping-bolt and moving the link and block by hand; butany other manner of adjustment, whereby a greater nicety or accu raey of adjustment could be obtained, may be adopted.

So far as I am aware I am the first to provide clamping devices in connection with a string-bar vibrator supported at both ends, whereby the bar may in effect be lengthen ed or shortened to modify its rate.

n As usual in electric vibrators, I prefer to mount the magnet M so that it can be adjusted toward or from the vibrator, and the manner in which I prefer to effect this adjustment is as follows: The magnet M is carperiphery and surrounded by a screw-th readed collar or ring, M. The disk is perforated on opposite sides, and through these perforations bolts, which screw into the bed-plate, loosely pass. By revolving the ring M', therefore, the disk carrying the magnet may be raised and lowered. By screwing down the bolts II2 the parts are iirml y locked or clamped.

I claim as my invention-n 1. The combination of an electrically-actuated vibrator with elastic or yielding tension devices for straining it.

2. The combination of a string-bar confined at both ends, an elastic or yielding tension device for straining said bar, and an electromagnet for Vibrating it.

3. The combination of a vibrating bar supported in a frame at both ends, a magnet for vibrating it, the adj listing-rod D, the adjusting-nut, and the spring.

4. The combination of a vibrating stringbar supported at both ends, a magnet for vibrating it, and a clamping device between its ends, adjustable lengthwise of the string-bar, to increase or decrease its vibratory length, substantially as set forth.

5. The combination of the vibrator supported at both ends, a magnet for actuating it, elastic or yielding tension devices for straining the bar, and clamping devices for clamping the bar between its ends to increase or diminish its vibratory length, substantially as set forth.

6. The combination of an electrically-actuated vibrator having apertures formed therein, anda contact against which the vibrator works, whereby the expansion dueto heating of the vibrator is taken up, substantially as set forth.

7. rIhe combination of a string-bar vibrator confined at both ends and having apertures formed therein, a contact on the vibrator in proximity to said apertures, an opposite contact against which the contact on the vibrator works,and a magnet for operating the vibrator.

8. The combination of the bed-plate, the magnet, the screw-threaded disk on which the magnet is mounted, its encircling screwthreaded adj listing-ring, and the bolts Il.

9. The combination of the adjustable electric contact-screw, the split block in which it works, and a clamping device for clamping the split block upon the screw to hold it in its adjusted positions.

In testimony whereof I have hereunto subscribed by name.

FRANK B. COLMAN.

fitnessesz E. C. DAVinsoN, HENRY D. HALL.

IOO

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